An Approximate Equation for the Pressure-Driven Volume Flow Across a Microporous

An approximate equation for the pressure-driven volume flow across a microporous membrane with
n pores per unit area is
w a2 / yð 6 P

A) Q _V = n $\pi$ a²/ $\eta$ ð $\Delta$ P
B) Q_V = A n $\pi$ a⁴ / 8 $\eta$ ð $\Delta$ P
C) Q _V = - AD ( $\Delta$ P - o $\delta$$\pi$ ) /ð
D) Q _V = n $\pi$ a⁴ / 8 $\eta$ ð $\Delta$ P
E) None of the above